The 46-year-old man was taken to hospital in a critical condition after being shot in the stomach in the home north of Brisbane.
Officers arrived at the Caboolture South residence about 10.30am in relation to a warrant before the man allegedly threatened them with a knife, police said.
A crime scene officer at the Caboolture South home where the shooting occurred. (Darren England/AAP PHOTOS)
"As a result of them attending that address, an altercation took place between a male occupant and the police," Detective Inspector Joe Zitny told reporters.
"This resulted in a police firearm being... discharged and a 46-year-old male has sustained an injury."
The man was taken to Royal Brisbane and Women's Hospital with "life-threatening abdominal injuries", he said.
The man remains under police guard at the hospital.
Police said two other people and a baby were located at the scene but were not injured.
"At this stage, they are witnesses and ultimately their information will form part of our investigation and give us a picture of what actually took place," Det Insp Zitny said.
The ethical standards command will investigate the incident.
Det Insp Zitny said he had spoken briefly to the officers after the incident.
"As you can appreciate, it's a very unpleasant circumstance and position to be in," he said.
"We will wrap support around them as best we can."
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